What is CVE-2026-54287?

CVE-2026-54287 is a medium-severity vulnerability in Honojs Hono, classified under Improper Encoding or Escaping of Output. CVSS score: 5.3/10. Published 2026-06-22.

How severe is CVE-2026-54287?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Honojs Hono

CVE-2026-54287

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on AWS Lambda, the ALB single-header response and the VPC Lattice v2 response join multiple Set-Cookie headers into one comma-separated…

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Honojs Hono — versions < 4.12.25

Weakness classification (CWE)

CWE-116 — Improper Encoding or Escaping of Output

References

security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-54287?: CVE-2026-54287 is a medium-severity vulnerability in Honojs Hono, classified under Improper Encoding or Escaping of Output. CVSS score: 5.3/10. Published 2026-06-22.
How severe is CVE-2026-54287?: Medium severity. CVSS v3 base score is 5.3 out of 10.